Background:
In a previous post, I discussed comparing the Mk7 GTI stock intake with some modifications using a BMC aftermarket panel air filter and a Mann OEM air filter. Performance differences attributable to the air filters were negligible.
The next logical comparison is of the Mk7 modified stock airbox, using the OEM filter, with an aftermarket intake.
Parts under test:
The modified stock Mk7 GTI intake system consists of the following:
- Air duct passenger rear side – covered.
- Air duct driver side – front opened.
- Lower airbox – hole added on the side facing ECU
- Mann air filter
- MST Performance inlet hose
- DBV2 turbo inlet elbow
The alternative intakes for comparison are the Blaze ATOM Race V2 and the Racingline R600.
The Blaze ATOM is fitted with a 56 mm turbo inlet flange, and the R600 uses the MST Performance inlet hose and DBV2 turbo inlet elbow (different from what is shown above.)
The intakes are tested on a Mk7 GTI equipped with a Mabotech M520 turbocharger operating with a Russell Road & Racing E50 tune.
Test Process:
The GTI is operated in fourth gear, and a full-throttle street pull is made, starting at around 2200 RPM and ending at around 6500 RPM.
The intakes are swapped, and this test is repeated.
Test Results:
The ambient air temperature during the data recording sessions was similar. The Racingline test takes place under 5 degrees Fahrenheit cooler weather than the stock and Blaze pulls.
The intake air temperature was similar for the three sessions. The stock airbox pull IAT falls between that of the R600 and Blaze ATOM.
Boost pressure is very similar for each of the intakes.
The turbocharger wastegate duty cycle (WGDC) is also very similar for each intake. The slight decrease in the R600 case could be due to the lower ambient air temperature.
Using the vehicle acceleration data to estimate horsepower and torque curves with Virtual Dyno shows similar results with each intake.
The peak WHP for each intake is as follows:
- Blaze ATOM – 505
- Racingline – 504
- Stock Mk7 – 502
Conclusions:
A modified stock Mk7 GTI air intake was compared with aftermarket Racingline and Blaze Performance intakes during acceleration at full throttle in fourth gear.
Logged vehicle performance data shows a negligible difference between the modified stock intake and the aftermarket intakes.
On a Mk7 GTI producing ~500 whp and operating at a boost pressure of 34 psi tapering to 32 psi, an aftermarket intake did not appear to improve performance compared with a modified stock GTI intake using an OEM Mann air filter.